OSAKA, Japan — Bryan Clay says he's ready to take on the world.

The rest of the world says it's ready to take on Bryan Clay.

And so the battle lines are drawn for the men's decathlon event at the 11th World Championships of Track and Field at Nagai Stadium.

Clay, 27, a Castle High School and Azusa Pacific University of California graduate, is cast in the role of defending champion in the 10-event struggle, which opens with the 100-meter dash tomorrow morning (tonight Hawai'i time) and concludes with the 1,500-meter run Saturday night.

He scored the biggest triumph of his life when he rolled up 8,732 points in brutal rainy, cold conditions to take the gold medal at the 2005 World Championships in Helsinki.

But some have pointed to his failures to finish at both the 2006 and 2007 USA Championships in Indianapolis as reason to doubt his full fitness for a world title defense.

There are some high-level doubters that Clay can win it again, including Track and Field News, the California-based magazine that calls itself "the bible of the sport."

"Track and Field News didn't even have me in the medal count, and I'm not sure why," Clay said at a recent press conference. "I've been the underdog many times.

"So, for me, this is usually the position that I'm in, and it was the same in Athens (where he took the silver medal at the 2004 Olympic Games.) "And I don't think there were many who thought I'd do well in Helsinki, either.

"It's a familiar position for me and where I like to be. I like to know that I'm the underdog and then go out and show everybody that I can do well."

Another expert analyst, Bob Ramsak, writing for the International Association of Athletics Federations, the global governing body for the sport, said "Bryan Clay will have his hands full."

In a meet in late May at Austria, only a bad day in the discus circle ruined Clay's hopes of running up a huge score. He still totaled 8,493 points.

Usually, his performances in the shot put, discus and javelin have been his strongest points, despite his 5-foot-11, 185-pound physique.

Many of his leading rivals tower over him but he's never let that worry him as he's climbed to the top of his event with a combination of great strength, superb technique and total dedication.

Just five men have ever scored more than Clay's career-best total of 8,820 points when he won silver at Athens in 2004. Those above him are Roman Seberle (9,026), Tomas Dvorak (8,994), American record-holder Dan O'Brien (8,891), Great Britain's Daley Thompson (8,847) and Germany's Jurgen Hingsen (8,832.)

Clay's bottom-line prediction: "I expect to be on American record pace throughout the meet but, more importantly for me, I expect to be ahead, or at my personal best, and how far ahead I don't know. That will depend on the conditions and how the competition is going."